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Quantum Computing

Quantum computing for business: what is real today and what is coming

SubNeta Engineering · 9 min read

Quantum computing attracts two kinds of bad advice: that it will change everything next year, and that it is decades from relevance and can be ignored. Both are wrong. The useful position for an executive is narrower: understand which problems quantum computers are built for, know where the hardware actually stands, and run small, honest experiments on the problems that matter to you.

What a quantum computer is good at

A classical computer stores bits that are 0 or 1. A quantum computer stores qubits, which can exist in superpositions and can be entangled with each other, so that certain calculations explore a vast space of possibilities in a way classical machines cannot efficiently imitate. This does not make them faster at everything. It makes them potentially far faster at a specific set of problems:

  • Optimization - portfolio construction, vehicle routing, scheduling, network design, where the number of combinations explodes.
  • Simulation of quantum systems - molecules and materials, for drug discovery, battery chemistry, and catalysis.
  • Certain machine-learning subroutines - sampling and kernel methods, still largely experimental.
  • Breaking today's public-key cryptography - the reason quantum matters to every organization, not only to the ones with hard optimization problems.

Where the hardware stands

Today's machines are in the "NISQ" era: noisy, intermediate-scale quantum devices with tens to a few thousand physical qubits and error rates that limit how long a computation can run before noise overwhelms it. Error correction - combining many physical qubits into one reliable logical qubit - has moved from theory to demonstration, and vendor roadmaps now target fault-tolerant machines with hundreds of logical qubits. Timelines vary by vendor, and it is prudent to assume they will slip; it is imprudent to assume they will never arrive.

Practical implication: no business advantage today from a pure quantum algorithm on production workloads - but real value from hybrid methods, quantum-inspired classical algorithms, and being ready when the hardware crosses the threshold.

Hybrid quantum-classical algorithms

Most near-term work uses hybrid algorithms such as QAOA (for optimization) and VQE (for chemistry), where a classical computer does most of the work and calls the quantum processor for the part it is good at. Quantum annealers take a different route to similar optimization problems. In many cases, the process of reformulating a business problem for these methods - as a QUBO or an Ising model - produces improved classical solutions on its own, which is a return on the investment before any quantum hardware is used.

How to start without the hype

  1. Pick one problem with a clear objective and a known classical baseline - the solver you use today and its solution quality.
  2. Formulate it for hybrid methods and run on simulators and cloud-accessible quantum hardware.
  3. Benchmark honestly against the baseline. Most experiments will show parity or worse today. That is data, not failure.
  4. Build the skills and the abstraction so that when hardware improves, you can re-run in weeks rather than starting over.

The part you cannot postpone

Whatever the timeline for quantum advantage in optimization, the timeline for quantum risk to cryptography is driving action now, because migration takes years and encrypted data is being collected today. That is the subject of our post-quantum cryptography article, and the first quantum project we recommend to nearly every client.

Want to discuss this with your own data in the room?

Bring a real system or a real document set - an expert will tell you honestly what's possible and what it takes.